This is Comet Hartley 2 as it appeared on the night of October 9/10, 2010 as it travelled through Perseus. The comet is the cyan glow at left, wth the Double Cluster at lower right and the complex of red nebulosity of IC 1848 / IC 1805 / IC 1795 at top. Technical: This is a stack of 5 x 2.5 minute exposures at ISO 1600 with Canon 5D MkII on 135mm L-series telephoto lens at f/3.2. Tracked the sky on Kenko SkyMemo tracking platform to follow the stars.
Comet Holmes (17P) at upper left and Comet Tuttle (8P) at lower right (as green spot), taken Dec 29, 2007 with 35mm Canon lens at f/2.8 and Canon 20Da at ISO 400 for stack of 6 x 2.5 minute exposures. Also includes M33 (below Tuttle) and M31, and clusters NGC 752 (middle) and M34 (left beside Holmes).
Comet Lovejoy (C/2014 Q2) at upper left as the blue glow, in the constellation of Andromeda, with the Andromeda Galaxy, M31, at lower left. The star cluster NGC 752 is left of the comet, and the galaxy M33 is at the left edge. The Double Cluster in Perseus is at upper right. The constellaiton of Cassiiopeia is at right. Taken Feb 9, 2015 from City of Rocks State Park, New Mexico. This is a stack of 5 x 2m15s exposures with the 50mm lens at f/2.5 and Canon 5D MkII at ISO 800, on the Star Adventurer tracking mount. Plus two exposures taken through the Kenko Softon filter layered in to add the star glows.